DENIERS SAY:

Galileo was also a skeptic — eventually he was shown to be more correct than the establishment trying to shout him down.

SCIENCE SAYS:

Climate scientists use evidence and logic. Climate deniers use ideology and politics. So which one is more like Galileo?

Galileo used scientific evidence to prove the Earth revolved around the sun, and not the other way around, even though his idea went against the common thinking and religious ideology of his time. So who is more like Galileo: climate scientists, or people who deny the reality of climate change? Climate scientists are using the evidence-based rules of science to arrive at their conclusions. Deniers are using politics and ideology. Climate scientists are fighting against an age-old perception that humans can’t affect the climate. Deniers are trying to reinforce that out-of-date idea. Climate scientists are being dragged into court when their conclusions are unpopular or inconvenient. Deniers are doing the dragging. So who is more like Galileo? You be the judge.

Additional info from Skeptical Science

Some climate change skeptics compare themselves to Galileo, who in the early 17th century challenged the Church’s view that the sun revolves around the Earth and was later vindicated. The comparison to Galileo is not only flawed; the very opposite is true.

1. Galileo was suppressed by religious/political authority, not scientists.

Galileo was not suppressed or “outvoted” by other early scientists. Many scientific contemporaries agreed with his observations and were appalled by his trial. Galileo was persecuted by the religious-political establishment — the Catholic Church — which in 1616 ordered him to stop defending his view of the solar system, which contradicted church dogma. After Galileo published his famous Dialogue, the Roman Inquisition tried him in 1633 for defying Church authority, and found him guilty of suspected religious heresy, forced him to recant, banned his books and sentenced him to house arrest for life. Galileo died eight years later.

2. Science is evidence-based; the most vocal skeptics are belief-based.

The key difference between Galileo and the Church concerned Galileo’s “way of knowing,” or epistemology. How is knowledge attained? Medieval scholarship and Catholic Church dogma relied on the authority of Aristotle and a literal interpretation of the Bible to place Earth at the center of the universe.

In contrast, Galileo’s views were not based on an infallible authority. His conclusions flowed from observations and logic. Galileo’s evidence- and logic-based method of inquiry later became known as the scientific method.

The vast majority of vocal skeptics are not engaged in climate research. The common bond uniting them, observers note, is an ideological belief system: Government regulation is bad, so problems that may require regulation must be resisted. From there, they search for ways to cast doubt on the science. Unlike Galileo and modern scientists, they do not change their view when presented with new evidence, because their position derives not from open-ended scientific inquiry, but from strongly-held ideological convictions.

In contrast, climate science applies the scientific method pioneered by Galileo. Scientists make observations, form logical hypotheses, then test their hypotheses through experiments and further observations. They follow the evidence wherever it leads.

The Church’s attack on Galileo and the skeptical assault on climate science are far from unique. History is full of examples where new scientific findings threatened powerful vested interests — whether religious, financial or ideological — and provoked a furious backlash.

3. The discovery of global warming overturned an age-old belief; the skeptics seek to restore it.

In arguing that the planets revolve around the sun, Galileo was challenging an idea that had dominated Western thought for over 1,400 years. Ever since Ptolemy (90-168 A.D.) codified Aristotle’s “geocentrism,” most philosophers/scientists had accepted the common-sense view that the Earth is the center of the universe, with the sun and planets revolving around us.

Similarly, the prevailing view throughout history was that people, through our own actions, could not possibly alter Earth’s climate on a global scale. Even into the 20th century, the overwhelming majority of scientists maintained, in science historian Spencer Weart’s words:

“ … the widespread conviction that the atmosphere was a stable, automatically self-regulated system. The notion that humanity could permanently change global climate was implausible on the face of it, hardly worth a scientist's attention.”

Some say climate science’s first “Galileo moment” came in 1896, when Swedish scientists Svante Arrhenius, after years of laborious hand calculations, predicted eventual global warming due to CO2 emissions. Others point to 1938, when a British steam engineer named Guy Stewart Callendar, after poring over old CO2 and temperature records, stood alone before the Royal Meteorological Society to argue that global warming was already happening.

Arrhenius and Callendar were ahead of their time, and failed to persuade others. In both cases, the scientific establishment found their calculations oversimplified and their evidence incomplete, certainly not convincing enough to overturn the ancient view that global climate was impervious to human acts.

Mainstream scientific opinion was slow to change. During the postwar science boom in the 1950s, early computers and advanced methods allowed scientists to directly investigate objections to Arrhenius’ and Callendar’s view. Using the new digital computers, Gilbert Plass found that more CO2 could indeed block more heat. Hans Suess analyzed radioactive isotopes to detect ancient carbon in the air, presumably from fossil fuels. Roger Revelle and Suess discovered that the oceans could not quickly take up additional CO2. David Keeling built the first sensor capable of accurately measuring atmospheric CO2 — just as Galileo had invented a more advanced telescope — and found that the CO2 level was indeed rising.

From 1960 to 1990, the evidence kept accumulating, from areas of study as far afield as geology, astronomy and biology. As the gaps in knowledge were filled, one by one, most scientists changed their views and gradually formed a new consensus: significant anthropogenic (human-caused) global warming was likely.

By 2000, the evidence was overwhelming. The climate pioneers were vindicated (Figure 1).

Figure 1: A brief history of climate change science.

Critics of climate science, backed by the alarmed fossil fuel industry, sprang into action in the late 1980s, when the mounting evidence led to calls for international action to limit CO2 emissions. They did not argue, like Galileo, for a revolutionary hypothesis based on new evidence, because they could not agree on one among themselves. They produced little new evidence. Instead, they searched for flaws in the research of others, and launched a public relations campaign to sow public doubt.

Unlike Galileo, climate skeptics were not trying to overturn an ancient view. Their goal was the opposite: to restore the age-old conventional wisdom, that, by itself, “human activity was too feeble to sway natural systems.” In clinging to this old view, the skeptics' stance more closely resembles that of the Catholic Church, which fought Galileo’s views for another 100 years after the scientific establishment had embraced them.